Method osi making vehicle tires



1. A. SWINEHART.

METHOD OF MAKING VEHICLE TIRES. APPLICATION FILED NOV. 6. 1920.

1 4'2 6, 927 Paten ted Aug. 22, 1922.

TIE-1 $2.5. 2.

,. umreo srarss PATENT OFFICE.

, AMES LsWINEHART, or AKRON, 01110.

METHOD OF 'MAKING VEHICLE TIRES;

To 'aZZ whomz't may concern:

Be it known that I, JAMns A. SWINEHART, aqcitizen ofthe United States, residing at Akron, in the county of Summitand State of Ohio,.have, inventedcertain new and useful Improvements in aMethod of Making Vehicle Tires, of which the following is a specification. H i Thisinvention relates to a method of making vehicle .tires,.especially casings having clencher beads, and the steps taken produce inthe end a casing-of the desiredform with.- out faults or malformation and permit the production of suchcasings in. large quantities. without variation .in form and quality.

Inmaking tire casingsaccording to well known practices, usingrigid metal molds, a certain percentage of imperfect casings will be produced, but notwithstanding, there are also advantages to ,be derived by the' use; of

. such'molds." Myobject is toemploy such molds to derive the-advantages gained by theiruse, andv to modify thesteps'heretofore taken so as to prevent the production of imperfect casings and toiminimize the losses.

- Thus, in the accompanying drawing, Figs. 1 and 2 represent two different molds, each figure being-a cross sectionthrough a divided mold and a core within. the mold.- The cores in said-figures are identical, and ,in

full and dotted lines the form given to the casing by the two molds shown in Figs. 1 and 2, respectively.

In practicing my method, a tire casing A is builtup step by step on an annular core B in the usual manner until the requisite number of plies of woven fabric or cord stock, together with the beading material and the tread of rubber, produce a beaded casing of a given thickness and weight corresponding roughly in outline to the finished product but slightly oversize.

This initial product A, together with the iron core B, is placed within a divided castmetal mold C having counter-part molding recesses 2 in their respective meeting faces, the contour and dimensionsof these molding recesses being substantially the same as desired in the final product excepting at the bead forming portions 3. Here the ridge or shoulder 4 in the mold which produces the Specification of Letters Patent.

m lication filed November 6, 1920. sm-m ne. 422,164.

P tentedu 22', 192 2.

clencher channelin the side of the casing is v rounded ona sweeping curve and the space between this ridge or shoulder 4 and the sloping side 5 of core B isrelatively wide and flaring to produce anoversized or overthick wall in thetire at this point and permitv an unobstructed movement of the bead stock toward the'base portion 6. On the other; handthe base portion 6 of the molding cavity which forms the seating portion for the tire, is of slightly less depth than that required to give the tire its true and final size; in otherv words this product will be toolarge at its inner diameter to properly fit a clencher rimof standard size. I I

The fabricated casing- A is subjected ton heavy pressure in this primary mold C while the rubber is in an uncured state and still plastic, and the mold, core and material are all cold.. Heating is not resorted to nor required at thisstage of operations, a'sit is my. aim to-firstform the tirewith an unfinishedbead before transferring the same to. a second moldD which is ,used to compress the first product to its, finished form.while the rubberis still plastic and in an uncured state. In pressing the casing ,while cold in mold C the separate sides of the casing are stretched over coreB toward thebead and base forming portions of the moldwithout buckling, wrinkling or folding the fabric or distorting it in any. objectionable Way because this primary mold is free from sharp bendsin its bead. forming surfaces and im-' poses no marked obstructions or irregulari ties tending to unduly stretch and strain the fabric in a single operation. The first step of compression is only intended to stretch the fabric and produce a bead corresponding roughly to its final contour approximately shown within the borders of the dotted lines in Fig. 3, and the rounding oli' or shortening of ribd in the forming mold C, Fig. 1, provides a free passage for the bead in its downward movement during this first stretching operation, and allows the bead to be set up higher or three-eigths of an inch, instead of three-sixteenths of an inch as customarily practiced. Upon the completion of the first compressing step the mold C is removed from the press and opened, and the core B, together with the partly completed tire casing A, is transferred and placed within the second cast iron mold D. The molding cavity in the sections of mold D has ap- C, exceptin proxirnatelj the same contour and dimen sions as the molding cavity in the first mold fo gnin I portion 9 is deeper or farther away from t e tread-forming portion of the tire casing in mold B as coinpired withmold C.

Thus, the ino1din% space between rib 8 of llfand mes oping side 5 of core B is as vied in comparison with thesame space Q a mold CfwhiIe the channel or space be {'8' and the base forming portion 9 is' s'onieW-hat deeper or greater" 11 1 mold D man thecor !e'sponoling',c'haniiel oi space in i Therefore wheiithepart1y formed "n'g is compressed Within the mold t e time and riibberfsides of the. casing mgstretchedva second time in a sli htly greater "dgree'fand the material comprising mabeaa portion of the'tire is" given its finish sad shapewi'thout subjecting the fabric to exeessive strainsl 'The shapi g and smoothing action-is more positive" and certain in p actieingthe successive steps herein deseri bed i'n contradistinction; to the former practice of producing such a beaded casing iii-asingleo ration; Furthel'nioieih the asv eeeild epemion will generally iron out an l ffiOVB Slitfii" imperfectionse Moreover, in i tiiillisflrfiiflg he partly finished easing from i eaway fo dsor imperfections are roaimed i in' the first molding operationythe the inol dft'o the mold an opportu'n it'y is given to examine and perceive any radical change' and malformation and to coriect thesaiiife before the secondv operation takes pIacePIt should beunderst'ood in this connection that the first step takes place in a cold press, and thatthesecond step takes place a fv-uicaniz'ing press where heat and ressure arei'mparted*coincidently to the When inoid Dis removed from the in its bead forming portions Where the c annel forming 'rib' S is smaller and extends farther into fliei cavity "than rib at in mold D. Moreover, the base or seatvuleanizingpressthe tire A" is 'a finished Vulcanized product.

What I claim is:

' 1 A 'n'i'ethod ofinaking tires, comprising thehstept ofmqlding a built-up tire casing While cold to approximately its finished contour and dimensions and withfa partly developed bead, and then molding and c'oinpressing and" stretch'ihg the casing to a slightly greater degree While heating and Vulcanizing the same andformiii'g afiiiished B dau'T". n 1

219A methodofmaking man ing haviiiig cle'ncher"beadsfeomprising the steps ofbui ing a tire casing of rubberand fabriciipon an ironhcor ancl placing said coije and clasiiig togethei' Within a'moid and pressing and molding the casing with partly finished beadrtiolis, and then tra sier ri g said core-a d partiy finished 'product tea-second i mold" and compressing said bead portions ih agre'at'er degiee'and vuicanizing the casing infits finished form. e

A method ofmakingtire-casing hay-1 ing cienclier beads, comprising't'he step 7 of compressing "and stretching it bu'flt-upbas ing" offabric "and; rubber in a limited degree while p'rodil'cing a clenche head roughly thei ein, and then" stretching the headedport'i'on'of thefcasin to s," eater n I degree while shapingthe-Ybe'a to its finished: contour under heat and'pressure;

*4; A method of making' tire casinghav ingu locking beads, (mnsfisting in moldingthe' fabricatedcasing "with pressure but Without heat" until aqoartiy finished head is formed smegma; 

